What exactly do sinus do?

I’ve had my sinus blocked for 6 months, and I haven’t noticed any changes with them blocked or cleared, besides intense pain. So what do sinus do for the body?

I feel your pain. Sometimes literally. My sinuses don’t clog up until winter and spring. When they aren’t doing that, they’re usually more snot than any dozen people need in their lifetimes. 'Tis often I wish I could have a sinusectomy.

As for your question, I think they’re there to help filter out allergens and other gunk out of the air. Or God has a sadistic streak.

They filter out gunk, and also contain your olfactory epithelium–in other words, you smell with them (and also with your sense of taste, etc etc).

In addition to filtering the air and being the residing place of the olfactory mucosa the sinuses also warm and humidify the air on the journey to the lungs. Without those processes being carried out the lungs could easily be damaged by exposure to cold, dry air. On the way back out the sinuses also extract excess moisture, which helps
Conserve water and prevent dehydration.

The nasdal sinuses really serve a lot of varied and useful purposes.

Too bad mine have been clogged for half a year. grumbles

I believe they also serve to make your head light enough for your neck to support.

Nope, they don’t do that calliope. If lightening the load was all that was required then the simplest solution would simply be not to include anything at all. It’s not like the sinuses have negative weight.

Hmmm… according to the American Rhinologic Society it’s a valid theory. It’s not that they have negative weight, but that the spaces take the place of skull, which would be heavier. At least that’s how my GP explained it to me.

You need to head down to your nearest Thai restaurant and have some tom yum soup. Should clear 'em out pretty quick, and usually it comes in big bowls so you’ll have leftovers to take home in case they get blocked up again later.

If that were the case then it would dimply be a case of removing the skull. The sinuses are certainly designed to be light, but they need to have a purpose aside form that or they would simply be replaced with nothing, which is far lighter than the sinuses, See the point? You don’t just build somehting to be light simply so it can be light. You build somehting light becuase wight os a constraint on an otherwise useful system.

Cecil’s thoughts on Why do we have sinuses? from More of the Straight Dope.

Sinuses filter out allergens? Then why do I still have allergies…?

I think the main purpose my sinuses serve is to enrich the pharmaceutical industry.

You have allergies because your immune system is hyperactive and looking for trouble. That is, it’s seeing harmless chunks of protein as a threat and is responding to them.

Your sinuses are tasked with air filtration, which is why they create thick, gluey mucus for dirt and pollen to get stuck in. Not the most appetizing thought, but there you are. This defensive response gets jacked up when the body sees something as a threat, which happens too often in allergic people.

If you removed your mucus membranes and turned your sinuses into completely empty holes (and I know you’ve been tempted), your lungs would need to cope with dry, dirty air, which would damage the delicate gas exchange structures that your blood uses to exchange carbon dioxide for oxygen.

Um, no. Over 99% of inhaled air doesn’t go thru the sinuses at all. It goes thru either the nasal passages or the mouth. The sinuses are chambers off of the nasal passages. See? We still don’t know why we have sinuses.


Is there any reason why they fill up in the first place, but don’t drain? I’m looking at surgery for these damned things. :mad:

Qadgop: Dammit, my theory makes sense. :stuck_out_tongue:

So, we really don’t know why we have sinuses? That’s a new one on me.

Cannibal fondue pots, maybe.

No kidding. I spend hours lying awake at night cursing the damn things, wondering why the hell I can’t just get them removed. Seeing as they plug my nose up so much that I’m forced to breath through my mouth, I don’t think I’d miss them.

In all seriousness: Are there major interventions possible for people with major sinus problems?

A common misconception. When you cannot breath thru your nose, it is your Nasal passages that are blocked, not your sinuses. See the illustration in my link. The sinuses are like huge rooms off of the main hallways that air travels thru. Sinuses get plugged when the doors to the sinuses get swollen and plugged, often via allergies or irritants.

Of course! How do you think ENT docs make their money? Endoscopic sinus surgery! Which is much better than the old style interventions, like drilling a hole thru the roof of the mouth and scraping everything out of the sinus, then packing it with gauze.

Another beautiful theory slain by an ugly fact… :wink:

And I can only imagine how that must feel afterwards. :eek: